1. Field of the Invention
The present invention relates to a cutting insert detachably mounted on an indexable cutting tool body, and a cutting tool which can detachably mount the cutting insert.
2. Description of the Related Art
Conventionally, for example, there are some cases where in a groove formed by processing using a rotary cutting tool, finishing processing is performed to side wall surfaces at both sides of the groove. For performing such two kinds of processing, that is, roughing processing and finishing processing of the groove, two kinds of rotary cutting tools are generally used. In addition, in a case of performing such two kinds of processing by using a single rotary cutting tool alone, two or more of processing processes shifted in processing positions are required. For such two kinds of processing, conventionally two rotary cutting tools each having a different processing width for roughing processing and finishing processing of the groove are used or for performing the finishing processing by a single rotary cutting tool used in the roughing processing of the groove, the single rotary cutting tool is moved relatively to a side wall surface of the groove after the roughing processing.
For example, Japanese Patent Laid-Open No. 2001-38517 shows an example of a conventional cutting insert and rotary cutting tool which can perform groove processing. Japanese Patent Laid-Open No. 2001-38517 discloses a side cutter as the rotary cutting tool applied to the groove processing. The cutting insert used in the rotary cutting tool is formed in a substantially rectangular plate shape, and includes an upper surface and a lower surface as two opposite surfaces, each having a rectangular shape, and outer side surfaces each having a trapezoidal shape. The cutting insert is formed in such a manner that a pair of outer side surfaces among the four outer side surfaces form rake surfaces, and the other pair of outer side surfaces and the upper surface form relief surfaces. A cutting edge is formed in the edge of the outer side surface as the rake surface. The cutting insert having such a shape is mounted on each of insert mounting seats alternately formed in both end surface sides of the tool main body, that is, the tool body by a screw penetrating through the upper and lower surfaces to use the lower surface as a seating surface. That is, since the cutting insert has a cutting edge in the right side and a cutting edge in the left side as the insert is viewed from the edge tip thereof, the cutting insert is a right hand insert, as well as a left hand insert.
The cutting insert disclosed in Japanese Patent Laid-Open No. 2001-38517 has the right-side cutting edge and the left-side cutting edge, as described above. However, these cutting edges are cutting edges used for the same kind of processing. Therefore in the cutting insert and the cutting tool disclosed in Japanese Patent Laid-Open No. 2001-38517, a plurality of cutting tools are still required or a plurality of processing processes by a single cutting tool are still required to perform roughing processing and finishing processing of the groove.